Henning Makholm wrote:
> Scripsit Josh Triplett <josh@freedesktop.org>
>>It would be useful, before proposing a GR to do so, to have a list of
>>all the packages currently in main which would become non-free if this
>>clause were abolished, as well as any well-known licenses which might be
>>affected.
>
> Did we ever find concrete evidence that TeX comes with a license to
> create modified versions under different names? The copyright notice
> at the top of tex.web presents only the patch option, and
> /usr/share/doc/tetex-bin/copyright is not of much help.
To the best of my knowledge, TeX is explicitly in the public domain, and
the only restrictions on it are based on the trademark on the name
"TeX". Trademarks cannot legally affect functional elements, in order
to avoid abusing trademarks, which are perpetual as long as they
continue to be used and enforced, to create other perpetual
restrictions. For example, if you make it a requirement to pass a
trademarked name to a function in order to use it, people may do so
without a trademark license from you. Filenames are a functional
element. Therefore, a trademark alone cannot restrict the use of a
given filename. (Not a lawyer, not legal advice, etc.)
Some searching around led to an article "The Future of TeX and
Metafont", written by Knuth, a copy of which is available at
<http://www.tug.org/tex-archive/digests/tex-mag/v5.n1>. From this article:
> I have put these systems into the public domain so that people
> everywhere can use the ideas freely if they wish.
[...]
> anybody can make use of my programs in whatever way they wish, as
> long as they do not use the names TeX, Metafont, or Computer Modern.
[followed by conditions for using the names based on a test suite]
Further searching reveals several sources that indicate the American
Mathematical Society obtained a trademark on the name TeX for the
purposes of enforcing those conditions. Given the limitations on the
scope of such a trademark, I don't believe this can render the program
non-free. In the worst case, it might be necessary to expunge
non-functional references to the names before making modifications.
As far as LaTeX goes, the LPPL has been fixed, though there is still a
need to do a license audit to check for packages which add additional
restrictions.
- Josh Triplett